Weight loss and high-protein, high-fiber diet consumption impact blood metabolite profiles, body composition, voluntary physical activity, fecal microbiota, and fecal metabolites of adult dogs.

Canine obesity is associated with reduced lifespan and metabolic dysfunction, but dietary intervention may aid in its management. This study aimed to determine the effects of restricted feeding of a high-protein, high-fiber (HPHF) diet and weight loss on body composition, physical activity, blood metabolites, and fecal bacteria and metabolites of overweight dogs. Twelve overweight dogs were fed a HPHF diet during a 4-wk baseline to maintain body weight and then fed to lose weight for 24 wk. Body composition, blood samples, voluntary physical activity, and fresh fecal samples were measured over time. After 24 wk, dogs lost over 30% of their initial body weight and had 1.4% weight loss per week. As expected, serum triglycerides, leptin, insulin, C-reactive protein, and interleukin-6 decreased with weight loss. The relative abundances of 4 bacterial phyla and over 30 bacterial genera were altered with weight loss. Fecal ammonia and secondary bile acid concentrations decreased, whereas fecal valerate concentrations increased with weight loss. Several correlations between fecal bacteria and physiological parameters were identified. Our results suggest that a HPHF diet and weight loss promote fat mass loss, reduce inflammatory marker and triglyceride concentrations, and modulate fecal bacterial populations and activity in overweight dogs.